Rolls-Royce says the TT-PM offers numerous advantages over traditional tunnel thrusters, including a 25 per cent increase in power output of from the same size propeller and a significant reduction in noise and vibration. It can be removed underwater, eliminating the need for dry docking.

Anders Almestad, President - Offshore, Rolls-Royce said: "We are delighted that Olympic Shipping is the first customer to select our new tunnel thruster.

"This cutting edge technology is suitable for a range of applications in offshore and merchant vessels, where operators will benefit from its high power output and rapid response to power demand, combined with exceptionally low noise levels."

"The new thruster is quiet, efficient and extremely durable," he said. "It is capable of running for thousands of hours in intensive operations such as the harsh conditions of the offshore oil and gas fields, where rapidly varying loads and alternating thrust directions are the norm."

The new thruster design concept comprises a permanent magnet motor in a rim, which drives the propeller in the centre. The permanent magnet motor consists of a stator that carries a number of electrical coil windings, and a rotor fitted with a number of very strong permanent magnets.

Having the motor in the rim frees up space directly above the thruster where thruster motors are normally located, making the thruster room available for other equipment or alternative use.